One or both of these flags must be present.
-- DMA_MEMORY_INCLUDES_CHILDREN - make the declared memory be allocated by
- dma_alloc_coherent of any child devices of this one (for memory residing
- on a bridge).
-
- DMA_MEMORY_EXCLUSIVE - only allocate memory from the declared regions.
Do not allow dma_alloc_coherent() to fall back to system memory when
it's out of memory in the declared region.